Hydraulic telescoping lifting jack



R. F. E. ySTEGEMAN iHYDRAULIC TELESCOPING LIFTING JACK Nov. 9,-194s.

2 SheetS-Sheet 1 Filed Aug. 11, 1945 FIG.I

v M v m, ,f www l I l dw l RAYMo Nb F.E.STEGEMAN Snventor Patented Nov. 9, 1948 2,453,350 HYDRAULIC TELESCOPING yLIFTING JACK v Raymond F. E. Stegeman, Rochester, N. Y., as-

signor to Bausch & Lomb Optical Company, RochcstenN. Y., a corporation of New York Applicationnughstfn, 1945, serial No. 610,324

v6 Claims.

This invention relates to lifting jacks and, more particularly, to the fluid pressure or hyraulically 'operated variety thereof, one object of the invention being to provide an improved lifting jack of the above variety having a concentric andfmore compact type'ofu construction.

Another yobject is to provide a lifting jack of the variety described comprising a plurality of concentrically arranged lifting members each operated by iluid pressure. y n s A further object is to provide suchma lifting jack comprising a plurality of concentrically arranged lifti'ngjmembers, one of which is operated by fluid pressure means and actuates a second fluid pressure means for loperating another of said lifting members.

Still a further object is to provide a lifting jack of the above nature comprising but few parts adapted to be economically manufactured and assembled and to operate efliciently with a minimum of adjustment or repair. n To these and other ends the invention resides in certain improvements and combinations oi parts, all as will be hereinafter more fully de# scribed, the novel features being pointed out in the claims at the end of the specification.

A In the drawings:

Fig. 1 is a central sectional elevation through a lifting jack embodying the present invention and showing the same with the :partsin lowered position, and

liig. 2 is a similar view showing the parts in partially raised position. I f The embodiment of the invention herein dis` closed by way of illustration comprises a base 5 at the center of which is an upwardly extending hollow standard or piston rodf having xed on itsV upper end, by any suitabley means, a piston I provided with packing 8, of any known or suitable variety. The piston rod 6 has an open upper end 9 and communicates at its lower end with any known or suitable means, indicated schematically at I0, for supplying and relieving fluid pressure throughthe opening in the rod. The means 10,., for example, may comprise an oil pressureor another hydraulic system as wellunderstood in the art. While the tubular piston rod l is4 shown in thepresent instance as Iextending through the base 5, it may obviously have its end mounted in the base in communication with a conducting passageway cored in the base` The lifting members comprise an inner cylinder I I mounted at its lower or inner end I 2 in a recess in a head I3. The head is of greater diameter than the cylinder, for a purpose hereinafter de- 2 scribed,` and comprises a plate I4 which'closes the lower Iend 'ofA cylinder II and has an opening concentric with the'cylinder for slidably receiving the piston rod 6. The plate is recessed as at I'to form a stuinng box about thevrodcomprising a suitable packing I6 and a gland I'l. The upper end of the cylinder II is closed by means of ,a head, la. i n Tel.

The lower cylinder headr I3 is preferably ex'- tended radially and recessed as at 2D to 4provide a mounting forsan outer cylinder I9 concentric with and spaced from the inner cylinder II and having its lower end fixed in the recess in the head, the cylinders I I and I9 and the piston rod 6 being concentrically arranged, as shown. The wall of the inner cylinder II is formed adjacent the head I3 with port openings 2I affording continuous communication between the inner and outer cylinders. The outer cylinder I9 has an open upper end, 22.

A second lifting member is provided by a tubular part, 23, extending downwardly through the open upper end 22 of the outer cylinder I9. The lower open end of the part '23 is formed withan enlargement, 24, provided with suitable packing 25 and a gland. or follower 26, so as to afford an annular piston head sliding in and closely fitting the annular space 21 between the inner and outer cylinders II and I9, as shown.v

The upper end of the part 23 supports a'liftin'g member, or sleeve, 28, having a closed upper end 29 providing the lifting step or surface of the jack. The walls of member 28 enclose the upper portion of the abovedescribed mechanism and extend down telescopically within a` stationary casing fixed on the base 5. lViernber 28 is preferably guided for movement within casing 3D, as by means of lugs `3l formed with openings Slidably fitting rod standards 32 fixed in the base. The members 28' and 30 thus effectively enclose, house and protect the working mechanism.` ,Y In operation,v oil or other iluid'pre'ssure issupfplied through the hollow standard or piston rod 6 tothe inner cylinder II above the stationary piston 1. This causes thel inner cylinder to move upwardly ,and carry with it its lower head IBancl the outer cylinder I lSI fixed to the same head. j A 's inner cylinder I I rises, the space 33'betweenlt and the piston rod 6 is reduced, thereby forcing the oil or other uid with which it is lled outwardly through the port openings 2| into space 21 between the inner and outer cylinders. Such increased pressure in space 21 presses upwardly on the annular head 24, raising its tubular part 23 which bears against and raises in turn the sleeve member 28 the upper end 29 of which forms the lifting surface of the jack. The parts continue to rise so long as fluid pressure is supplied to the inner cylinder or until its lower head I3 engages the piston 'I and is thus stopped. Release of the uid pressure in the inner cylinder allows the lifting members to descend until head I3 rests on: basev E as shown in Fig. 1.

The invention thus ai'ords a simple and practical mechanism in which one lifting member is raised by uid pressure means and actuates in turn a second fluid pressure means which raises a second lifting member, so that movement of one lifting member is addedto that of another with cumulative effect. complished by a type of construction in which the parts are concentrically nested for telescopic movement relative to one another in an arrangement which is exceedingly compact and requires but few parts.

It. will thus be seen that the invention accomplishes its objects and While ithas been herein described. by reference to the details of a preferred` embodiment, it is to be understood thatv such description is intended in an illustrative, rather than in a limiting sense, as it is contemplated that various modifications in the construction and arrangement of the parts will readily occur to those skilled in the; art, within the scope. of the appended claims.

I` claim:

. 1. A lifting jack. comprising a base,y telescoping inner a-nd outer cylinders, means. movably supporting said cylinders on said base, said outer cylinder having a connection with. said inner cylinder for movement thereby, means movable in said outer cylinder in response to. pressure therein, fluid .pressure responsive means for moving said inner cylindeny and fluid pressure generating means actuated by said inner cylinder and having a iluid medium communicating. with said outer cylinder for moving said. pressure responsive means. v

2. A lifting jack having a base-concentric inner and outer cylinders, means movably supporting said cylinders on saidbase, said outer cylinder having a connection with said inner cylinder for movement. thereby, means movable in said outer cylinder in response to pressure therein, uid pressure responsive means for moving said inner cylinder, and fluid pressure generating means actuated by said inner cylinder comprising port means between said cylinders and a uid medium connecting said cylinders through said port means for actuating said pressure responsive means by the movement of said inner cylinder.

3. A lifting jack having a base, concentric inner and outer cylinders, means movably supporting said cylinders on said base, said outer cylinder having a connection with said inner cylinder for movement thereby,r means movable in said outer cylinder in response to pressure therein, a hollow piston. rod extending. through an end of said inner cylinder and provided therein with a piston, means for supplying fluid under pressure through said rod to one end of said inner cylinder for moving the same, and uid pressure generating means actuated by said inner cylinder compris- This function is aclen 4 ing port means between the otherr end of said inner cylinder and said outer cylinder and a iluid medium connecting said cylinders through said port means for moving said pressure responsive means by the movement of said inner cylinder. 4. A lifting jack comprising a base, a hollow piston rod extending from said base, a head sliding on said rod, concentric inner and outer cylinders each mounted atone end on said head concentric with said rod, said inner cylinder being closed at its opposite end and provided adjacent said base with port means communicating with said outer cylinder, a uid pressure medium connecting said cylinders through said port means, means movable in said outer cylinder in response to Huid pressure therein, piston means on said rod in said inner cylinder in spaced relation with said base and means for supplying uid under pressure through said rod to said inner cylinder on the side of said piston opposite said port means, for moving said head and. cylindersand thereby moving said pressure responsive. means.. 5,.. A lifting jack comprising a base, a hollow piston rod extending from said base, ank inner cylinder having its inner end slidably mounted on said rod and closed at its outer Yend, av piston on said rod in said inner cylinder, anouter cylinder spaced concentrically from said inner cylinder and having a connection therewith for movement thereby, said inner cylinder having a port opening therein belowsai'd piston communicating with said vouter cylinder, a fluid pressure medium connecting, said cylinders through said port opening,r lifting means movable in said outer cyl-inder in response tothe. pressure. therein produced by the movement of said inner cylinder, and. means for supplying. fluid under pressure through said rod to said inner cylinder above said piston for simultaneously moving said cylinders and said lifting means.

6. A lifting jack comprising a base, av hollow piston rod extending fromsaidbase, an inner cylinderV closed at its .outer end and having its inner end slidably mounted on said rod, a piston on said rod in said inner cylinder, an outer cylinder spaced concentrically fromr said inner cylinder and having a connectiontherewith for movement thereby, a member having an annular piston head slidably tted inthe. space between said.

cylinders, said `cylinders having a communicating opening between the adjacent. inner ends thereof below said piston and piston head, a fluid pressure medium connectingr said cylinders through said opening, and means for supplying fluid under pressure through said rod to said inner cylinder above said piston for moving said cylinders and thereby moving said member.

RAYMOND F. E. STEGEMAN.

anrnnsriens orrnn The :following references are of record in the file of this. patent:

UNITED sTArEs PATENTS 7 Sibley i Mar. 6, 1900 

